The Ultimate Wrist Watch Pip-Boy-style

Based on a Motorola Defy smartphone, this "ultimate wrist watch" has a custom-written app to light up with the right information whenever the wearer orients the watch in time-telling position.

(Ultimate wrist watch - Pip-Boy-style video)

The really cool feature of this app turning the screen on automatically when you look at the watch and turning it back off when your done. You should need to fumble around with the power button to check the time. This is accomplished my monitoring the acclerometer. When the phone is at the write angle it turns on (the angle and threshold is adjustable). Monitoring the acclerometer requires acquiring a partial wake lock. This of course will decrease your phone's battery life, but that's the price you pay for the ultimate watch. To help save the battery, the app will release the wake lock if it detects no movement for a long period (like an hour). Turning the screen on restarts the service.

Fans of the science fiction movie Predator will remember the alien wrist display; among its various functions - detonate nuclear blast.

Mark brushed back the soft green sleeve of his upper garment and pressed several buttons on the wide bracelet he wore upon his left wrist... He controlled [the bird's] passage with the wristband and saw through its eyes upon the tiny screen in the bracelet's center.
(Read more about Zelazny's wristband viewer)

And, of course, as the title of the article suggests, fans of the Fallout game series might be reminded of the RobCo Pip-Boy 3000.

The Pip-Boy 3000 is a hand-held electronic device produced by RobCo Industries and is one of several Pip-Boy models that were issued as standard to Vault-Tec Vaults. The device has numerous functions, and its capable of displaying the character's stats, area maps, inventory, Geiger counter, and radio. It is also possible to illuminate the screen to a level that is sufficient to light the area immediately around the user, acting as a makeshift lantern in darkened areas.
(From Pip-Boy 3000)